The present invention relates in general to a prosthetic pylon, and in particular to a prosthetic pylon supporting the weight of a patient on an enclosed compressible volume of fluid.
Individuals who lose all or part of a leg have a residual leg stump to which a prosthetic foot is often attached through an elongated pylon. Such a pylon is typically a rigid member made with a material, like a carbon-fiber composite or aluminum, which provides the rigidity necessary to support an individual""s weight.
This rigidity can be problematic, because it often makes conventional pylons too stiff for comfortable movement. Each step on such a pylon can be awkward and painful, rather than cushioned and resilient like a natural leg. Therefore, there is a need in the art for a pylon which adequately supports an individual""s weight and is more cushioned and resilient than conventional pylons.
An inventive pylon includes a first end portion connected to a patient""s leg stump and a second end portion connected to a prosthetic foot. The second end portion is rotatable and axially movable relative to the first end portion about and along a longitudinal axis of the pylon, respectively. Preferably, the second end portion includes a piston, and the first end portion includes a piston chamber receiving the piston. The piston chamber encloses a compressible volume of fluid through which substantially all of the patient""s weight applied through the patient""s leg stump is supported. The compressible volume of fluid is preferably sealed so that it can be pressurized. Also, a torsional spring couples the piston and piston chamber and resists relative rotation between the piston and piston chamber without supporting any substantial portion of the patient""s weight applied through the patient""s leg stump. The present invention thus advantageously provides a pylon which is more cushioned and resilient than conventional pylons.